A conventionally known configuration of a torsional vibration damper includes a damper spring device including a plurality of springs arrayed in a circumferential direction, and a rotary inertia mass damper (as shown in, for example, Patent Literature 1). In this torsional vibration damper, the damper spring device includes a plurality of sliding blocks that are respectively placed between adjacent springs and arranged such that an entire outer circumferential surface is supported by a drive-side damper element (input element) to be slidable. The rotary inertia mass damper includes the driven-side damper element arranged to rotate integrally with a turbine shell of a turbine wheel and configured to include a sun gear of a planetary gear; a driven-side damper element (output element) arranged to rotate integrally with a turbine hub of the turbine wheel and configured to serve as a carrier of the planetary gear; a pinion gear rotatably supported by the driven-side damper element and arranged to engage with the sun gear; and a ring gear configured to serve as a mass body engaging with the pinion gear. In the torsional vibration damper of this configuration, when the driven-side damper element is rotated (twisted) relative to the driven-side damper element, the springs of the damper spring device are deflected, and the ring gear as the mass body is rotated with relative rotation of the drive-side damper element to the driven-side damper element. This configuration causes a torque according to an inertia (moment of inertia) of the ring gear as the mass body and a difference in angular acceleration between the drive-side damper element and the driven-side damper element to be applied to the driven-side damper element and improves the vibration damping performance of the torsional vibration damper.